| 摘要 |
<p>PURPOSE:To measure a relatively short distance simply and inexpensively, by a doppler radar having two antennae, two counting parts for measuring frequency and an operation part for calculating a distance. CONSTITUTION:When DC bias voltage is applied to a gun diode 11, electric waves are emitted from antennae A1, B1 by oscillation and the reflected waves from an object are received by the antennae A1, B1 while dopplar frequencies DELTAf1, DELTAf2 are obtained from the amplitude of the encircling line of the transmitting and receiving waves thereof. These waves are rectified by a mixer diode 10 and amplified by obtaining AC of the doppler frequencies to be shaped to a pulse waves by wave form shaping devices A4, B4. Pulse lines are counted by counting parts A5, B5 to read the frequencies DELTAf1, DELTAf2 and enter an operation circuit A6 to calculate the distance of the object to be measured. This distance is compared to a preliminarily set distance issueing an alarm and a distance stopping a moving object by a comparator A7 and alarm or stop treatment is taken by the output thereof.</p> |
